The present invention relates to a method for the insertion of modifications into software procedures in communication systems.
In modern communications systems, besides a higher processing speed, there is a demand for availability to all subscribers at all times. This has the consequence that, for example, a communications system cannot be shut down for removal of software errors, as is the case for other data processing equipment. For this reason, methods have been developed that enable a rapid installation at short notice of small modifications in the software procedures of the communications system. With these patches, as they are known, small software modifications can be rapidly and efficiently brought about.
For simpler logical coding errors, the faulty code is thereby simply overwritten. However, if additional code must also be added during the execution of the program, the installed patch is connected with what is called a "knapsack." This contains the additional programming code required for the removal of the logical error. The correction of the modified programming code occurs during subsequent execution in that the procedure branches to the installed knapsack at the corresponding modification point, and after execution of the same, a jump back to the original programming code takes place. This process is controlled via an allocated patch management that is implemented as a data library. The addresses of the knapsacks allocated to the patches are stored therein in table form.
European patent application EP 0 492 251 describes a method for the installation at short notice of error corrections in the software procedures of a communications system. It is disclosed therein how a patch is installed by high-priority patch processes, with exclusive reservation of the relevant processors. However, it is not disclosed or taught how patches are installed in software structures having generic modules or having reusable modules.